The field of the invention is plumbing fixtures and the invention relates more particularly to piping a control system for permitting the accumulation of water or other liquids in a box and emptying the accumulated liquid when the box is full.
A pressure sensitive controller is shown in U.S. Pat. No. 6,311,718, assigned to the assignee of the present invention. The specification and drawings of this patent are incorporated by reference herein for purposes of background. A waste disposal system is shown in U.S. Pat. No. 6,385,789, which utilizes a vacuum operated discharge valve. The system utilizes an electrically operated control valve and is operated by depressing a flush button.
U.S. Pat. No. 6,349,425 also shows a vacuum toilet system. The unit is operated in response to a flush command. The same unit is shown in U.S. Pat. Nos. 6,353,942 and 6,370,709. A vacuum drainage system is shown in U.S. Pat. No. 6,305,403. A buffer box used in a vacuum drainage system is shown in U.S. Pat. No. 6,311,717.
It is an object of the present invention to provide an accumulator box which will empty liquid from the accumulator box when the liquid reaches a predetermined level without the use of any electrical signal.
The present invention is for an accumulator for collecting a volume of a liquid, including means for removing the liquid when the liquid reaches a predetermined level in the accumulator. The accumulator has a box for holding a volume of liquid and the box has an outlet port near its bottom for passing liquid out of the box. An inlet opening allows liquid to pass into the box and to be accumulated in the box. A first control pipe is held within the interior of the box and has an open bottom near the bottom of the box and has a closed top. A second control pipe is also held within the interior of the box and has an open bottom spaced further away from the bottom of the box than the open bottom of the first control pipe. A conduit passes from the closed top of the first control pipe to the inlet port of a pressure sensitive controller. The first conduit has a first check valve permitting the flow of gas only in the direction of the first control pipe. A second conduit leads from the closed top of the second control pipe to a point where it joins the first conduit at a location in the first conduit between the first check valve and the inlet port of the pressure sensitive controller. The second conduit has a second check valve therein permitting the flow of gas only in the direction of the pressure sensitive controller. As the level of liquid rises in the box, it initially increases the air pressure within the first control pipe, but the first check valve prevents this increase in pressure from passing to the inlet of the pressure sensitive controller. As the liquid level rises further, it reaches the open bottom of the second control pipe. As the pressure within the second control pipe increases, this increase in pressure is passed to the inlet port of the pressure sensitive controller. When the level of liquid has reached a predetermined distance above the open bottom of the second control pipe, the pressure is sufficient to actuate the pressure sensitive controller, thereby opening a drain valve and emptying the contents of the box. The present invention is also for the process of operating the accumulator. The drain valve is closed when the liquid level drops below the bottom of the first control pipe.